From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Fri, 30 May 2025 15:40:04 +0000 (-0300)
Subject: sparc: Fix argument passing to __libc_start_main (BZ 32981)
X-Git-Tag: glibc-2.42~172
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=404526ee2e58f3c075253943ddc9988f4bd6b80c;p=thirdparty%2Fglibc.git

sparc: Fix argument passing to __libc_start_main (BZ 32981)

sparc start.S does not provide the final argument for
__libc_start_main, which is the highest stack address used to
update the __libc_stack_end.A

This fixes elf/tst-execstack-prog-static-tunable on sparc64.
On sparcv9 this does not happen because the kernel puts an
auxv value, which turns to point to a value in the stack itself.

Checked on sparc64-linux-gnu.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
---

diff --git a/sysdeps/sparc/sparc32/start.S b/sysdeps/sparc/sparc32/start.S
index 694b020ce0..cef7c96cac 100644
--- a/sysdeps/sparc/sparc32/start.S
+++ b/sysdeps/sparc/sparc32/start.S
@@ -73,6 +73,10 @@ _start:
      be NULL.  */
 	mov	%g1, %o5
 
+  /* Provide the highest stack address to update the __libc_stack_end (used
+     to enable executable stacks if required).  */
+	st	%sp, [%sp+23*4]
+
   /* Let libc do the rest of the initialization, and call main.  */
 	call	__libc_start_main
 	 nop
diff --git a/sysdeps/sparc/sparc64/start.S b/sysdeps/sparc/sparc64/start.S
index c9c25c2e47..08e1e77210 100644
--- a/sysdeps/sparc/sparc64/start.S
+++ b/sysdeps/sparc/sparc64/start.S
@@ -74,6 +74,10 @@ _start:
      be NULL.  */
 	mov     %g1, %o5
 
+  /* Provide the highest stack address to update the __libc_stack_end (used
+     to enable executable stacks if required).  */
+	stx	%sp, [%sp+STACK_BIAS+22*8]
+
   /* Let libc do the rest of the initialization, and call main.  */
 	call    __libc_start_main
 	 nop